So, since I was out of my depth, I got some help this morning.  Here's what I learned.  Your regex was fine, but the original's `(.*)` was a bit greedy and an alternative of `([^']+)` was suggested.

What do you think about `FILE_PATTERN = /([^\t\n]+)(?:\t'{2}?([^']+)'{2}?)?/`as an alternative?   Your pull is fine as is, but I am interested in your thoughts.  I may create a new pull later.